O-acetylation of typhoid capsular polysaccharide confers polysaccharide rigidity and immunodominance by masking additional epitopes.

ABSTRACT: In this work, we explore the effects of O-acetylation on the physical and immunological characteristics of the WHO International Standards of Vi polysaccharide (Vi) from both Citrobacter freundii and Salmonella enterica serovar Typhi. We find that, although structurally identical according to NMR, the two Vi standards have differences with respect to susceptibility to de-O-acetylation and viscosity in water. Vi standards from both species have equivalent mass and O-acetylation-dependent binding to a mouse monoclonal antibody and to anti-Vi polyclonal antisera, including the WHO International Standard for human anti-typhoid capsular Vi PS IgG. This study also confirms that human anti-Vi sera binds to completely de-O-acetylated Vi. Molecular dynamics simulations provide conformational ration

SUBMITTER: Hitri K 

PROVIDER: S-EPMC6997886 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature